objtool/klp: Add correlation debugging output

Add debugging messages to show how duplicate symbols get correlated, and
split the --debug feature into --debug-correlate and --debug-clone.

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

diff --git a/tools/objtool/include/objtool/warn.h b/tools/objtool/include/objtool/warn.h
index 595ee800966729275e1fa7ce807ff0310e9d71e9..a9936d60980c1f3c47ab93e2754d7d4265c46006 100644 (file)
--- a/tools/objtool/include/objtool/warn.h
+++ b/tools/objtool/include/objtool/warn.h
@@ -109,7 +109,7 @@ static inline char *offstr(struct section *sec, unsigned long offset)
 #define ERROR_FUNC(sec, offset, format, ...) __WARN_FUNC(ERROR_STR, sec, offset, format, ##__VA_ARGS__)
 #define ERROR_INSN(insn, format, ...) ERROR_FUNC(insn->sec, insn->offset, format, ##__VA_ARGS__)
 
-extern bool debug;
+extern bool debug, debug_correlate, debug_clone;
 extern int indent;
 
 static inline void unindent(int *unused) { indent--; }
@@ -148,15 +148,21 @@ static inline void unindent(int *unused) { indent--; }
                      (unsigned long long)checksum);                    \
 })
 
-#define __dbg_indent(format, ...)                                      \
+#define dbg_correlate(args...)                                         \
 ({                                                                     \
-       if (unlikely(debug))                                            \
+       if (unlikely(debug_correlate))                                  \
+               __dbg(args);                                            \
+})
+
+#define __dbg_clone(format, ...)                                       \
+({                                                                     \
+       if (unlikely(debug_clone))                                      \
                __dbg("%*s" format, indent * 8, "", ##__VA_ARGS__);     \
 })
 
-#define dbg_indent(args...)                                            \
+#define dbg_clone(args...)                                             \
        int __cleanup(unindent) __dummy_##__COUNTER__;                  \
-       __dbg_indent(args);                                             \
+       __dbg_clone(args);                                              \
        indent++
 
 #endif /* _WARN_H */

diff --git a/tools/objtool/klp-diff.c b/tools/objtool/klp-diff.c
index a9c993298b82f090a5ba36ee092f3c6ad15b6dcb..ed3bf1c55001a18fc69515752d8ddd4fec2185cb 100644 (file)
--- a/tools/objtool/klp-diff.c
+++ b/tools/objtool/klp-diff.c
@@ -33,6 +33,9 @@ struct export {
        char *mod, *sym;
 };
 
+bool debug, debug_correlate, debug_clone;
+int indent;
+
 static const char * const klp_diff_usage[] = {
        "objtool klp diff [<options>] <in1.o> <in2.o> <out.o>",
        NULL,
@@ -40,7 +43,9 @@ static const char * const klp_diff_usage[] = {
 
 static const struct option klp_diff_options[] = {
        OPT_GROUP("Options:"),
-       OPT_BOOLEAN('d', "debug", &debug, "enable debug output"),
+       OPT_BOOLEAN('d', "debug", &debug, "enable all debug output"),
+       OPT_BOOLEAN(0, "debug-correlate", &debug_correlate, "enable correlation debug output"),
+       OPT_BOOLEAN(0, "debug-clone", &debug_clone, "enable cloning debug output"),
        OPT_END(),
 };
 
@@ -583,6 +588,14 @@ static struct symbol *find_twin(struct elfs *e, struct symbol *sym1)
        else if (csum_orig == 1 && csum_patched == 1)
                match = csum_last;
 
+       if (!match)
+               return NULL;
+
+       if (name_orig != 1 || name_patched != 1)
+               dbg_correlate("find_twin(): %s%s -> %s%s",
+                             sym1->name, is_func_sym(sym1) ? "()" : "",
+                             match->name, is_func_sym(match) ? "()" : "");
+
        return match;
 }
 
@@ -686,10 +699,14 @@ static struct symbol *find_twin_suffixed(struct elf *elf, struct symbol *sym1)
                match = sym2;
        }
 
-       if (count == 1)
-               return match;
+       if (count != 1)
+               return NULL;
 
-       return NULL;
+       dbg_correlate("find_suffixed_twin(): %s%s -> %s%s",
+                     sym1->name, is_func_sym(sym1) ? "()" : "",
+                     match->name, is_func_sym(match) ? "()" : "");
+
+       return match;
 }
 
 /*
@@ -742,6 +759,10 @@ static struct symbol *find_twin_positional(struct elfs *e, struct symbol *sym1)
        if (idx_orig != idx_patched)
                return NULL;
 
+       dbg_correlate("find_twin_positional(): %s%s -> %s%s",
+           sym1->name, is_func_sym(sym1) ? "()" : "",
+           match->name, is_func_sym(match) ? "()" : "");
+
        return match;
 }
 
@@ -998,7 +1019,7 @@ static struct symbol *clone_symbol(struct elfs *e, struct symbol *patched_sym,
        if (patched_sym->clone)
                return patched_sym->clone;
 
-       dbg_indent("%s%s", patched_sym->name, data_too ? " [+DATA]" : "");
+       dbg_clone("%s%s", patched_sym->name, data_too ? " [+DATA]" : "");
 
        /* Make sure the prefix gets cloned first */
        if (is_func_sym(patched_sym) && data_too) {
@@ -1375,7 +1396,7 @@ static int clone_reloc_klp(struct elfs *e, struct reloc *patched_reloc,
 
        klp_sym = find_symbol_by_name(e->out, sym_name);
        if (!klp_sym) {
-               __dbg_indent("%s", sym_name);
+               __dbg_clone("%s", sym_name);
 
                /* STB_WEAK: avoid modpost undefined symbol warnings */
                klp_sym = elf_create_symbol(e->out, sym_name, NULL,
@@ -1426,7 +1447,7 @@ static int clone_reloc_klp(struct elfs *e, struct reloc *patched_reloc,
 }
 
 #define dbg_clone_reloc(sec, offset, patched_sym, addend, export, klp)                 \
-       dbg_indent("%s+0x%lx: %s%s0x%lx [%s%s%s%s%s%s]",                                \
+       dbg_clone("%s+0x%lx: %s%s0x%lx [%s%s%s%s%s%s]",                                 \
                   sec->name, offset, patched_sym->name,                                \
                   addend >= 0 ? "+" : "-", labs(addend),                               \
                   sym_type(patched_sym),                                               \
@@ -1481,7 +1502,7 @@ static int clone_reloc(struct elfs *e, struct reloc *patched_reloc,
        if (is_string_sec(patched_sym->sec)) {
                const char *str = patched_sym->sec->data->d_buf + addend;
 
-               __dbg_indent("\"%s\"", escape_str(str));
+               __dbg_clone("\"%s\"", escape_str(str));
 
                addend = elf_add_string(e->out, out_sym->sec, str);
                if (addend == -1)
@@ -2121,6 +2142,11 @@ int cmd_klp_diff(int argc, const char **argv)
        if (argc != 3)
                usage_with_options(klp_diff_usage, klp_diff_options);
 
+       if (debug) {
+               debug_correlate = true;
+               debug_clone = true;
+       }
+
        objname = argv[0];
 
        e.orig = elf_open_read(argv[0], O_RDONLY);

diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index 1c3622117c33cf53c496a07832c3ea94ee463c18..a4e139dee7e9fb6e90607e5934146224112a9bfd 100644 (file)
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -16,9 +16,6 @@
 #include <objtool/objtool.h>
 #include <objtool/warn.h>
 
-bool debug;
-int indent;
-
 static struct objtool_file file;
 
 struct objtool_file *objtool_open_read(const char *filename)